Folding implement frame with weight transfer

ABSTRACT

A folding implement frame having seven sections in a use position and nine sections when folded. The frame design allows a frame having a width of greater than 27 meters to be folded into a transport position having a width of less than eight meters and a height of less than six meters. The hydraulic system transfers weight to the center frame section during folding and unfolding to enhance stability. The hydraulic system uses accumulators to minimize the amount of oil reduction in the tractor reservoir resulting from extension of the hydraulic cylinders of the implement. Implement raise and lower cycle times are minimized by a helper cylinder to lift the frame main section when the entire implement weight is on the main section and allowing a smaller cylinder to lift the frame main section in the use position for shorter cycle times to raise and lower the implement.

FIELD

An implement frame is disclosed and in particular, a frame for anagricultural implement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an implement frame illustrating a main sectionand multiple wings;

FIG. 2 is a side view of a locking hinge assembly between two of thewings with the hinge assembly in the locked field use position;

FIG. 3 is a perspective view of the locking hinge assembly of FIG. 2.

FIG. 4 is a side view of the locking hinge assembly of FIG. 2 with thehinge unlocked and in a folded position;

FIG. 5 is a rear view of the frame of FIG. 1 showing the left side inthe field use position;

FIGS. 6-8 are rear views of the frame, like FIG. 5, showing the leftside the frame illustrating the folding sequence;

FIG. 9 is a rear view of the frame showing the entire frame in thefolded transport position;

FIG. 10 is a hydraulic schematic of the weight transfer system for framefolding;

FIG. 10A is an alternative hydraulic schematic for the frame weighttransfer system;

FIG. 11 is a hydraulic schematic of the oil exchange reduction systemfor reducing the amount of oil exchanged from the tractor when extendingthe cylinder rods to un-fold the frame;

FIG. 12 is a hydraulic schematic of an alternative embodiment of the oilexchange reduction system;

FIG. 12A is a hydraulic schematic of a further alternative embodiment ofthe oil exchange reduction system;

FIG. 13 is a side view of the main frame section illustrating the framelift wheel assembly in the frame lowered position;

FIG. 14 is a side view like FIG. 13 with the frame in the raisedposition;

FIG. 15 is a perspective view of the main frame section lift wheelassembly illustrating the main frame helper lift cylinder; and

FIG. 16 is a hydraulic schematic illustrating of the main frame helperlift cylinder circuit; and

FIG. 17 is a hydraulic schematic of an alternative hydraulic circuit forthe main frame lift cylinder.

DETAILED DESCRIPTION

An agricultural implement 20 is shown in FIG. 1. Implement 10 is an airhoe drill for use with an air cart to plant seeds. However, the presentinvention can apply to any type of implement and is not limited to anair hoe drill or even to an agricultural implement. The implement 10includes a frame 22 comprising multiple sections as described in greaterdetail below, a plurality of wheel assemblies and a hitch 24 to connectthe implement to a prime mover such as a tractor to move the implementalong the ground in a travel direction shown by the arrow 26. Implement20 can be directly attached to a tractor or connected behind an air cartthat is in turn connected to a tractor.

The frame 22 has a main or center section 30 to which the hitch 24 isconnected. The main section is supported on front and rear main wheelassemblies 32. The wheel assemblies are mounted on pivot arms to enablethe frame 22 to be raised and lowered relative to the ground. The framemain section has left and right sides 34 and 36 respectively relative tothe travel direction.

A plurality of left and right wings extend from the center section 30.Only the right side wings are shown in FIG. 1 for purposes of clarity.The left side is a mirror image of the right side. The entire frame isshown in FIGS. 5-9. Left and right first or inner wings 40 are pivotallyattached to the left and right sides of the main section at inner ends44 of the inner wings respectively. Each inner wing is pivotal about arespective inner wing axis 46 and each inner wing has an outer end 48.The inner wings are supported on wing wheel assemblies 42 adjacent theouter ends 48 of the inner wings 40. Outboard of the inner wings areleft and right middle or second wings 50. The middle wings 50 have innerand outer ends 54 and 58 respectively and are pivotally attached at theinner ends 54 to the outer ends 48 of the inner wings for rotation aboutmiddle wing axes 56. The middle wings do not have supporting wheelassemblies.

Outboard of the middle wings are left and right rigid wings 70. Therigid wings 70 have inner ends 74 and outer ends 78. The rigid wings arepivotally coupled to the outer ends of the middle wings for rotationabout rigid wing axes 76. The rigid wings are supported at the outerends by wing wheel assemblies 72. The rigid wings are coupled to themiddle wings by locking hinge assemblies 100 described in detail below.The locking hinge assemblies hold the rigid wings in place to preventrotation about the rigid wing axes 76 when the implement is in the fielduse position shown in FIGS. 1 and 5. The middle and rigid wings act as asingle unit with the wing wheel assemblies 72 supporting both the middleand rigid wings.

Outboard of the rigid wings are left and right outer wings 80. The outerwings have inner and outer ends 84 and 88 respectively and are pivotallyattached at their inner ends to the outer ends of the rigid wings 70.The outer wings rotate about outer wing axes 86. Wing wheel assemblies82 support the outer wings at the outer ends 88 thereof.

The locking hinge assemblies 100 are described with reference to FIGS.2-4. A pivot joint 102 couples the rigid wing 70 to the middle wing 50and defines the rigid wing axes 76. A guide arm 104 has one end 106coupled to the middle wing at pivot joint 108. The other end of theguide arm 104 is coupled to the rod 114 of a hydraulic cylinder 112 bypivot joint 110. The cap end of the cylinder 112 is attached to themiddle wing at pivot joint 116. A connecting arm 120 is also attached tothe rod 114 and the guide arm 104 at the pivot join 110. The oppositeend 122 of the connecting arm 120 is coupled to the rigid wing 70 at apivot joint 124. As the rod 114 is retracted, the path of the pivotjoint 110 is controlled by the guide arm 104. The connecting arm movesalong with the guide arm 104. This causes the rigid wing to rotate aboutthe rigid wing axes 76, to raise the rigid wing from the field useposition shown in FIGS. 2 and 3 to the folded transport position shownin FIG. 4. In the field use position shown in FIG. 2, pressure in thecylinder 112 holds the rigid wing in place with the surface 126 of therigid wing firmly butted against the surface 128 of the middle wing.

Implement 20 is shown in FIGS. 1 and 5 in a field use position in whichthe main section of the frame and the wings are generally aligned withone another in a horizontal orientation. While shown as being generallyhorizontal, this is when placed on level ground. The inner wings areallowed a certain amount of rotation about the inner wing axes 46 toallow the inner wings to follow the ground contours. Likewise, thejoined middle and rigid wings are allowed some rotation about the middlewing axes 56 while the outer wings are allowed to rotate about the outerwings axes 86, all to follow the ground contours.

A plurality of hydraulic cylinders are provided to fold the implement 20from the field use position of FIGS. 1 and 5 to a folded transportposition shown in 9. The folding sequence is described below. Hydrauliccylinders 140 are connected to the frame main section 30 and the innerwings 40. The cylinder rods of the cylinders 140 are coupled to brackets142 on the inner wings in a slot 144. The slotted connection of the rodto the bracket allows for limited rotation of the inner wings about theinner wing axes as the implement is moved over the ground to enable theimplement to follow the ground contours. Similarly, hydraulic cylinders150 are connected to the inners wings 40 and the middle wings 50.Hydraulic cylinders 180 are connected to the rigid wings and the outerwings. Slotted connections of the rods of cylinders 150 and 180 allowfor limited movement of the wings as described above enabling the wingsto follow the ground contours.

Folding of the implement 20 from the field use position to the foldedtransport position is accomplished as follows. First the frame islowered relative to the wheel assemblies. The fold sequence is theninitiated and the frame is raised to its uppermost position. The groundworking tools 28 are then retracted if they are of a retractable design.Folding begins by first actuating cylinders 180 to rotate the outerwings 80 about the outer wings axes 86. The outer wings are rotatedapproximately 180 degrees to a position in which the outer wings overliethe rigid wing as shown in FIG. 6. The outer wing wheel assemblies 82are then retracted relative to the frame, that is, the wheel assembliesare moved to the position relative to the frame they are in when theframe is lowered in the field use position.

The middle wings 50 and the rigid wings 70 are raised together as afixed unit with the hinge assemblies 100 still locked. The middle andrigid wings are raised by actuation of the cylinders 150 and are raisedtogether until the middle wings 50 are raise to about a twenty degreeangle. Before doing so, the cylinders 140 are retracted to apply alifting force on the inner wings 40. The lifting force is not sufficientto lift the inner wings but to transfer weight from the inner wings tothe center section 30. This improves stability of the frame duringfolding and also reduces the load on the inner wing wheel assemblies 42.This weight transfer is described in more detail below. After the middlewings are raised twenty degrees, the locking hinges 100 are released byoperation of the cylinders 112 and the rigid wings are rotated about theaxes 76 about 90 degrees to extend at approximately a right anglerelative to the middle wings. The cylinders 150 are further actuated torotate the middle wings 50 a total of approximately 90 degrees about themiddle wing axes 56 to the position shown in FIG. 8. Now the middlewings are extending upwardly with the rigid wings extending laterallyabove the inner wings and with the outer wings between the inner andrigid wings. The rigid wing wheel assemblies 72 are then retractedrelative to the frame.

The next step in the folding sequence is the actuation of the cylinders140 to now rotate the inner wings approximately 90 degrees to the foldedtransport position shown in FIG. 9. The inner wings wheel assemblies 42are then retracted. The inner wings are now extending upwardly, themiddle wings extend laterally inwardly, the rigid wings extenddownwardly and the outer wings extend upwardly beneath the middle wingsand between the inner and rigid wings. During the folding operation, theouter wings are rotated a total of approximately 450 degrees from thefield use position to the folded transport position. The rigid wingsrotate 270 degrees from the field use position to the folded transportposition. The middle wings rotate 180 degrees from the field useposition to the folded transport position while the inner wings onlyrotate 90 degrees from the field use position to the folded transportposition.

To fold the implement, the locking hinge joint 100 is unlocked allowingthe rigid wings to rotate relative to the middle wings about the rigidwing axes 76. The implement frame 22 operates as a seven section framein the field use position and as a nine section frame in the foldedtransport position. This enables the implement to be folded into asmaller configuration for transport than if it remained a seven sectionframe. As noted previously, the middle wings do not have wheelassemblies connected thereto. The wing wheel assemblies are only mountedto the wings that are oriented upright in the folded transport position.This helps to minimize the overall height of the implement in the foldedtransport position as there are no wheel assemblies extending upwardlyfrom the middle wings. Wing wheel assemblies 42 on the inner wingsextend laterally and depending on the size of the tools and wheelassemblies may increase the transport width of the implement 30 but notthe height.

The implement frame, by having seven section in the field use positionand nine sections in the folded transport position enables a frame to beconstructed that is greater than 27 meters in width in the field useposition but is folded to a transport position that is less than eightmeters in width and less than six meters in height. The implement shownhas a 96 foot width in the use position and a transport position widthof 23 feet and height of 18 feet. This is slightly smaller than thetransport dimensions of the 75 foot wide frame disclosed in U.S. Pat.No. 7,497,269. This results in a machine with a significantly greaterare covered per pass in the field compared to the machine of the '269patent without any increase in the transport dimensions.

A portion of the hydraulic system of the implement 20 is shown in FIG.10. Due to the number of wings on the implement, when rotating themiddle wings 50 between the folded transport position and the field useposition, it is beneficial for stability of the implement and to reducethe load on the inner wing wheel assemblies 42, to transfer weight fromthe inner wings 40 to the main section 30. The weight transfer wasmentioned above in connection with the folding of the frame. The weighttransfer is accomplished by the hydraulic circuit shown in FIG. 10.Hydraulic lines 200 and 202 connect to the tractor hydraulic system todelivery oil to the inner wing cylinders 140 and to the middle wingcylinders 150. Valves 204 and 206 control the flow of oil to and fromthe inner wing cylinders 140. Valves 214 and 216 control the flow of oilto and from the middle wing cylinders 150. To unfold the frame 22 fromthe folded transport position to the field use position, the inner wingcylinders are extended first by opening the valves 204, 206. Oil issupplied to the cylinders 140 by the line 200 and returned from thecylinder by the line 202. This rotates the inner wings about the innerwing axes 46 from the upright transport position in FIG. 9 to thegenerally horizontal use position FIG. 8. The valves 204 and 206 arethen closed. The valves 214 and 216 are then opened to extend the middlewing cylinders 150. While doing so, oil pressure is delivered throughthe pressure regulating valve 218 to the rod end of the inner wingcylinders 140 while the pilot operated check valve 220 is opened toallow oil to flow from the cap ends of the inner wing cylinders. Thisretracts the rods of the inner wing cylinders 140 to the end of theslots 144. The pressure in the cylinders 140 creates a lifting force onthe inner wings but the pressure is regulated by the valve 218 to not besufficient to lift the inner wings. This transfers weight from the innerwings to the main section. The added weight on the main section keepsthe implement stable during unfolding of the middle wings and reducesthe load carried by the inner wing wheel assemblies 42.

FIG. 10A shows an alternative hydraulic system for accomplishing theweight transfer. Here, the system is electro-hydraulically controlledwith the used of solenoid controlled valves 222 and 224 controlling theoil flow back to the inner wing cylinders 140 for weight transfer.

Weight transfer to the main section 30 is also beneficial during thefolding operation. This is accomplished by opening all of the valves204, 206, 214, 216 and supplying oil through the line 202 and returningoil through the line 200. The cylinder rods are all retracted until theyreach the ends of the slots. The pressure in the inner wing cylinders140 pulls on the inner wings and transfers weight to the main section.The pressure needed to actually lift the inner wings is greater than thepressure needed to lift the middles wings such that the middle wingcylinders 150 will continue to retract while the inner wing cylindersheld stationary. Once the middle wings are fully rotated, the hydraulicpressure will increase until it is sufficient to retract the rods of theinner wing cylinders 140 and thereby lift the inner wings. While it ispreferred to apply a lifting force on the inner wings for weighttransfer without actually lifting the inner wings, it is possible toslightly lift the inner wings before folding the middle wings.

The need for weight transfer to the main section during folding is dueto the large weight being moved when the middle wings are being folded.Weight transfer is not limited to a nine section frame but can be usedwith other frame configurations as well. The nine section frame, due toits size, has a large weight to be lifted when folding the middle wings.The weight transfer is beneficial. However, weight transfer may still beused with a frame having fewer than nine sections if the frame issufficiently heavy.

When extending the rods of the hydraulic cylinders, more oil isintroduced in the cap end of the cylinder than is given up from the rodend of the cylinder. The difference in oil volume is the physical volumeof the rod itself. With the implement 20 having many large cylinders tofold the frame, the additional volume of oil going into the cap end ofthe cylinder than coming out of the rod end to extend all of thecylinders to unfold the implement may exceed the amount of oil availablefrom the tractor hydraulic system reservoir.

To avoid taking too much oil from the tractor reservoir, the implementhydraulic system includes one or more accumulators 250 (FIG. 11). Whenthe rods are retracted, the accumulators store a portion of the oilcoming from the tractor. This results in the amount of oil coming fromthe tractor being more equal to the amount of oil being returned to thetractor from the cap end of the cylinders, thereby reducing the changein the oil level in the tractor reservoir. Later, when the rods areextended and more oil flows into the cap end of the cylinders than flowsfrom the rod end, the accumulators return oil to the tractor. The oilflow from the rod ends of the cylinders combined with the oil from theaccumulators more closely matches the oil flow into the cap end of thecylinders. This again reduces the magnitude of change in the reservoiroil level. The result is that the changes in oil level in the tractorreservoir are within acceptable limits.

The attached schematic shows the implement hydraulic system. The tractorselective control valves (SCV) 252 and 254 control the oil flow in andout of the implement. To retract the rods of the cylinders, shown hereas one cylinder 256, oil flows in from the tractor SCV 252. The oil flowis divided by a mechanical flow divider 258. In this embodiment, thedivider 258 is comprised of two gear motors 260, 262 tied together by ashaft 264. The displacements of the two motors are fixed and therebydetermine the ratio of the oil flow split. For example, the motors maybe sized to split the oil flow 85/15. Any desired ratios can be used. Inthis example, fifteen percent of the oil flows to the accumulator 250while eighty five percent flows to the rod end of the cylinder 256through the check valve 266. The pressure in the line 268 opens thepilot operated valve 270 in the line 272 connected to the cap end of thecylinder 256. This allows oil to flow back to the tractor through theSCV 254 to the tractor reservoir. Since a portion of the oil from thetractor is diverted to the accumulator, more oil is needed to retractthe cylinders such that the oil from the tractor is more equal to theoil returned to the tractor then if there was no accumulator.

To extend the rod, oil flows in through the SCV 254. Pressure in theline 272 opens the pilot operated valve 274 allowing oil on the rod sideof the cylinder to flow back through the flow divider to the tractor.Pilot pressure in the line 272 opens check valve 276 thereby allowingoil in the accumulator to also flow back through the divider to thetractor. This produces a more equal flow of oil to and from the tractorso that the net change in the reservoir oil level is within acceptablelimits. Other arrangements of the hydraulic system components can beused to accomplish the same function.

One alternative hydraulic system arrangement is to add dummy cylinderson the implement that operate in the opposite direction so that as therod of the active cylinder 256 is retracted, the rod on the dummycylinder is extended. See FIG. 12. There, as the rod of the activecylinder 256 is retracted, the rod of the dummy cylinder 257 isextended. In this manner, the dummy cylinder acts as the accumulatorwith no need for a flow splitter. As one cylinder takes in more oil thanit discharges, the other cylinder discharges more oil than it takes in.In such a system, there would be no change in the tractor reservoir oillevel if there is a dummy cylinder for each active cylinder. The dummycylinders must be anchored on each end to structure to ensure they movewith the active cylinders and not extend or retract without theappropriate oil pressure. FIG. 12A shows an alternative schematic forusing dummy cylinders as the reservoir. Here, the dummy cylinder 278 isvented to atmosphere with the pressure controlled by the pressureregulating valve 280. Other types of flow splitters may be used otherthan the dual motors shown. The above system to reduce the amount of oilexchanged with the tractor is needed as the implement 20 is intended tobe attached to a separate prime mover such as a tractor. This ensuresmaximum compatibility of the implement with a broad range of tractors.If the frame is part of a self-propelled vehicle, the vehicle hydraulicsystem would have a reservoir sized to have sufficient capacity toextend all the hydraulic cylinders.

The wheel assemblies are coupled to their respective frame section bypivot arms rotatably mounted to the main section or wings to enable theframe to be raised and lowered relative to the ground. The pivot arm 300is mounted to the main section by a pivot joint 302 which defines anaxis 304. The main wheel assembly 32 is attached to the pivot arm. Ifthe pivot arm 300 is rotated clockwise as viewed in FIG. 13, the mainsection 30 of the frame is raised upward. A linkage, not shown, connectsthe pivot arm 300 on the front wheel assembly 32 to the pivot arm 303 onthe rear wheel assembly so that the front and rear of the frame israised and lowered together. Such linkages are generally known.

The frame is raised at the end of each pass in a field to turn theimplement around. Once turned, the frame is lowered to reengage thetools in the ground. The frame is also raised to support the implementoff the ground when transported to and from the field. When raised inthe folded transport position, all the weight of the implement iscarried by the main wheel assemblies 32 on the frame main section 30. Tocarry the larger load, the main wheel assemblies 32 are larger than thewing wheel assemblies. Likewise, the hydraulic cylinders necessary tomove the pivot arms 300 will be larger than the cylinders to pivot thearms carrying the wing wheel assemblies. However, with the larger thecylinder, more oil needs to flow into and out of the cylinder to extendand retract the cylinder rod. Using a large cylinder on the main wheelassemblies will by necessity require longer raise and lower times whenmaking turns at the end of each pass even though in the field useposition the weight on the frame main section wheel assemblies is lower.The longer lift and lower cycle time decreases machine productivity. Toavoid the increased cycle time, the main wheel assemblies 32 areprovided with two hydraulic cylinders for lifting. One cylinder 306 issized to lift the main section when in the field use position and onlythe weight of the main section needs to be supported by the cylinder306. A second helper cylinder 308 is provided to increase the loadcarrying ability to support the load on the main wheel assemblies whenthe frame is in the folded transport position.

Cylinder 308 is connected to the pivot arm 300 through a swing arm 310,pivotally mounted to the pivot arm 300 by a joint 312. The swing arm 310allows the pivot arm 300 to move only by the operation of the cylinder306 when desired. However, when it is desired to use both cylinders 306and 308 to raise the frame, the swing arm 310 bears against the tube 314fixed to the pivot arm 300 to rotate the pivot arm and raise the frame.

A hydraulic schematic for operating the cylinders 306 and 308 is shownin FIG. 16. The main valve 320 opens to extend the rod of main framecylinder 306 and the wing cylinders to raise the frame. A second valve322 controls the operation of the helper cylinder 308. With both valvesopen, both cylinders are actuated. With only the valve 320 open, onlythe valve 306 is actuated. The valve 322 is opened when the foldsequence is initiated with the frame in the lowered position. Initiationof frame folding is mentioned above in the description of the foldsequence. Then, when the frame is raised, both cylinders 306 and 308 areactuated to lift the frame. This places the swing arm 310 in contactwith the tube 314 when lifting the frame.

An alternative arrangement of the “helper lift cylinder” is shown inFIG. 17. This arrangement only requires a single hydraulic cylinder 354at each of the two front wheel assemblies to raise the main section ofthe frame 30. Oil is supplied and returned through lines 350, 352connected to a selective control valve (SCV) of the tractor. To extendthe rod of lift cylinder 354, the valve 356 is opened, allowing oil toflow from the rod end of the cylinder and oil to flow in the cap end toextend the rod. This is used when lifting the frame for folding. In thefield, however, when lifting and lowering the frame for turns, therecirculation valve 358 is opened and the valve 356 is closed. Thisallows oil to flow from the rod end of cylinder 354 to the cap end whenlifting. The only oil needed from the tractor through the line 350 isthe oil for the volume of the rod. Thus, the time needed to lift theframe is reduced as only a small amount of oil is needed. When loweringthe frame, valve 356 remains closed and valve 358 is opened. Oil flowsfrom the cap end through the valve 358 to the rod end. The extra oil,(the volume of the rod) is returned to the tractor through the line 350.

While this alternative circuit for reduced raise and lower cycle time isshown with only one lift cylinder 354, two smaller cylinders can bearranged in the circuit in parallel in place of one large cylinder.Depending on the particular cylinder sizes, two smaller cylinders may beless expensive than one large cylinder. The cylinders 306, 308 of FIG.16 and associated mounting structure constitute a hydraulic actuatorassembly. Likewise, the cylinder 354 of FIG. 17 constitutes a hydraulicactuator assembly.

The hydraulic systems, as described above, operate the hydraulicactuator assemblies in first and second modes. In the first mode, thehydraulic actuator assemblies move the pivot arms at a first speed. Inthe second mode, the hydraulic actuator assemblies move the pivot armsat a second speed. With the embodiment of the hydraulic system as shownin FIG. 16, the first mode is with only the valve 320 open and thecylinder 306 operating at a faster speed. In the second mode, both thevalves 320 and 322 are opened and both cylinders 306, 308 are operatedat a second, slower speed. With the embodiment of the hydraulic systemshown in FIG. 17, the first mode with the faster speed is with the valve358 open and the valve 356 closed. The second, slower speed mode is withthe valve 358 closed and the valve 356 open.

Having described the implement, it will become apparent that variousmodifications can be made without departing from the scope as defined inthe accompanying claims.

1. A method of folding an implement frame, the frame supported on wheelsfor movement over the ground in a travel direction, the frame furtherhaving a main section with left and right sides relative to the traveldirection, left and right first wings having inner ends pivotallyattached to the main section at the left and right sides thereof, eachfirst wing pivotal about a respective first wing axis and having outerends, left and right second wings pivotally attached to the outer endsof the first wings, each second wing being pivotal about a respectivesecond wing axis, and a hydraulic system including first wing cylinderfor pivoting the first wing about the first wing axis and a second wingcylinder for pivoting the second wing about the second wing axis, themethod comprising the steps of: actuating the first wing cylinders toapply a lifting force to the first wings to transfer weight from thefirst wings to the main section; while maintaining the lifting force onthe first wings, actuating the second wing cylinders to pivot the secondwings about the second wing axes to thereby fold the frame from a fielduse position to a folded transport position; and after the second wingshave been pivoted to respective folded transport positions, furtheractuating the first wing cylinders to pivot the first wings to theirfolded transport positions.
 2. The method as defined by claim 1 whereinthe lifting force applied to the first wings during folding of thesecond wings is insufficient to lift the first wings off the ground. 3.The method as defined by claim 1 further comprising unfolding the framefrom the folded transport position to the field use position by:actuating the first wing cylinders to pivot the first wing about thefirst wing axis from a folded position to a field use position; thenactuating the first wing cylinders to apply a lifting force to the firstwings to transfer weight from the first wing to the main section; andsimultaneously actuating the second wing cylinders to pivot the secondwings from the folded transport position to the field use position.
 4. Afolding implement comprising: a frame supported on wheels for movementthe ground in a travel direction, the frame further having: a mainsection with left and right sides relative to the travel direction andhaving main wheel assemblies supporting the main section above theground; left and right first wings having inner ends pivotally attachedto the main section at the left and right sides thereof, each first wingpivotal about a respective first wing axis and having outer ends, thefirst wings each having at least one wing wheel assembly supporting thefirst wings above the ground; and left and right second wings pivotallyattached to the outer ends of the first wings, each second wing beingpivotal about a respective second wing axis, and the implement furtherhaving a hydraulic system including first wing cylinder for pivoting thefirst wing about the first wing axis and a second wing cylinder forpivoting the second wing about the second wing axis, the hydraulicsystem configured to apply a lifting force to the first wing to transferweight to the main section and while holding the first wingsubstantially in a use position actuating the second wing cylinder topivot the second wing about the second wing axis.